Several previous studies have demonstrated that the relative cerebral blood volume (rCBV) correlated with the histologic grade of gliomas and investigated the prognostic value of the tumor CBV for survival.In current study, We hypothesized that, the temporal changes during anti-angiogenesis therapy in specific regions of high and low perfusion in glioblastoma might predict the efficacy of bevacizumab.Since there is no mature PET tracer directly image Vascular Endothelial Growth Factor (VEGF) in China,we use 18F-Galacto-arginine-glycine-aspartic acid (RGD)—— a new tracer for PET imaging of αvβ3 by testing Standardized uptake value mean (SUVmean),Standardized uptake value max (SUVmax) and tumor to non-tumor tissue ratios (T/NT) to indirectly reflect the VEGF expression. The integrin αvβ3 is an important receptor affecting tumor growth, local invasiveness, and metastatic potential. Specifically, αvβ3 is highly expressed on activated endothelial cells during angiogenesis.